Moncalvo and others (2002; citation below) have compiled DNA evidence for 877 mushroom species, arriving at 117 clades of genetically related mushrooms. The clades containing most of the waxy caps and the omphalinoid mushrooms are represented below; I have conflated the branches of the Moncalvo et al. cladogram in order to paint with broad strokes. The five "groups" comprising these mushrooms are represented in boxes, and the various nested clades are represented within them.

The Reader's Digest condensed version is: The waxy caps and omphalinoid mushrooms are all mixed up, but there are recognizable clades within the broader mess that hold together fairly well and are not necessarily big surprises. While there is enough "bad news" in these findings to spread around for everyone, as far as traditional morphology-based taxonomy is concerned, there is also "good news"--for the late Lexemuel Hesler and Alexander Smith, whose subgenera Hygrocybe and Hygrophorus (which they subordinated to the genus Hygrophorus in 1963) are largely upheld as coherent groups; for Scott Redhead, who with others separated Chrysomphalina from Gerronema; and even for me, since the clades largely uphold differences in ecological roles, grouping together mushrooms that are mycorrhizal, saprobic, symbiotic with moss or lichens, and so on (regular readers are probably growing sick of my continual insistence on ecology).